The invention relates to a double pressurized container for under-cup charging and a double pressurized product using the same. More specifically, the present invention relates to improvements for facilitating under-cup charging in a double pressurized product which is equipped with a container main body with an opening at its upper end, an attached mounting cup for closing the opening, and an inner bag which has flexibility and which is interposed between the container main body and the mounting cup.
There has been known such a double pressurized product as a dispenser or aerosol product, which houses a flexible inner bag in its container main body and also which charges the inner bag with a content, i.e. concentrate to be discharged and also charges such a propellant as a pressurized gas between the inner bag and the container main body. The content housed in such a double pressurized product can be directly charged into the inner bag via an ejecting valve or through an opening in the inner bag. The propellant, on the other hand, is charged by either of two methods of charging it through a charging valve independently disposed at a bottom of the container main body or charged through a gap between a flange portion of a mounting cup and a bead portion of the container main body directly before the ejecting valve is crimped to the opening in the container main body using the mounting cup, which is so-called an under-cup charging method.
A double pressurized product equipped with a charging valve needs additional machining of its container main body and mounting of an independent charging valve, thus increasing its manufacturing cost. Therefore, an under-cup charging method has been proposed so far. This under-cup charging method, however, needs to charge a propellant through a gap between its inner bag and a container main body to be sealed in an air-tight manner finally. With this, in particular, in such a type of a double pressurized container that a flange portion of the inner bag is hung at bead portion disposed in an opening in the container main body, the inner bag needs various devices such as having vertical ribs for securing a passage for the passage (see, for example, Japanese Patent Application Laid-Open Nos. Sho-56-84270 and Sho-57-104571).
Also, since a propellant is charged with a high pressure of 0.3-5.0 Mpa, it may enter the inner bag at a gap between the inner bag (its flange portion) and the mounting cup (its curved flange portion) through between the neck portion of the inner bag and the rising wall of the mounting cup. Also, as mentioned above, the propellant (particularly in the case of a nitrogen gas, which has a lower solubility into the concentrate) is charged with a high pressure, part of the propellant which penetrated into the inner bag through the gap may cause a burst of the inner bag, which is a problem. The above-mentioned Japanese Patent Application Laid-Open Nos. Sho-56-84270 and Sho-57-104571 suggest that an adhesive agent or a sealant should be interposed between the inner bag and the mounting cup in order to prevent such penetration.
Japanese Patent Application Laid-Open No. Hei-9-2551, on the other hand, suggests such a method for manufacturing a double pressurized product that a propellant should be charged between the container main body and the inner bag beforehand and then part of the propellant leaked into the inner bag should be discharged by, for example, vacuum suction and then a content should be charged into the inner bag. With this method, no propellant may enter the inner bag. With this method, moreover, the inner bag, when empty, is engaged with and held at a bead portion of the main body, so that the engagement need not to be heavy, thus making it possible to disengage it easily. Also, Japanese Utility model Publication No. Hei-3-4373, though not relating to under-cup charging, discloses a method of folding back the flange portion of the inner bag 2-ply, to omit a gasket.
The above-mentioned method of interposing an adhesive agent or a sealant between the inner bag and the mounting cup is difficult to put into practice in the present-day assembly-line mass-production step portions whereby the inner bag and the mounting cup are manufactured independently of each other and then mounted at a charging step portion. In addition, the method by the above-mentioned Japanese Patent Application Laid-Open No. Hei-9-2551 of under-cup-charging a propellant beforehand and removing part of the propellant entered into the inner bag and then charging the inner bag with a content needs to charge the content against an inner pressure, thus being undesirable because of its double-step portion operations.
The present invention attempts technologically to minimize as much as possible the penetration of a propellant. into an inner bag without changing the conventional under-cup charging method as much as possible.
It has been found that such penetration of a propellant through a gap can be reduced to some extent by enhancing the strength of sealing between the inner bag and the mounting cup. The inner bag, however, has a flexibility and the flange portion of the inner bag cannot be prevented from being lifted, so that it is impossible to prevent penetration sufficiently. With this, the Inventor has analyzed and discussed about a mechanism of penetration into the inner bag at the time of under-cup charging with a conventional double pressurized product. As a result, the Inventor has found that in the case of a double pressurized container using a container main body having a bead portion, a gasket placed inside the curved flange portion of the mounting cup has a significant function on the penetration of a propellant into the inner bag.
That is, in such a double pressurized product, as shown in FIG. 19a, in a curved flange portion 102 of a mounting cup 101 is housed a rubber-made ring-shaped gasket 104 for sealing a gap between the curved flange portion and a bead portion 103 of a container main body. Then, as shown in FIG. 19b, after assembly, the gasket 104 is abutted against the bead portion 103 directly in order to provide a secure sealing function, so that an outer diameter of a flange portion 106 of an inner bag 105 is made a little smaller than that of the gasket 104.
Therefore, when, during assembly, a valve assembly is once mounted on the upper part of the container main body and then lifted up for under-cup charging, as shown in FIG. 20, the gasket 104 is in close contact with the curved flange portion therein and, on the other hand, an outer periphery of the flange portion 106 of the inner bag is separate from the surface of the gasket 104 or only a slightly abutted against it. Therefore, it is considered that at the time of under-cup-charging, the outer periphery of the flange portion 106 is lifted up, thus permitting a propellant to enter the inner bag through a gap 107.
With this, the Inventor has devised the present invention, considering that the above-mentioned problem of penetration of a propellant at the time of under-cup charging can be prevented significantly by enhancing a degree of contact between the inner bag and the mounting cup and also by employing a sealing structure between the mounting-cup and the container main body basically providing no gasket or, even if a gasket is provided, by employing such a sealing structure as not to give rise to the above-mentioned problem.
From the viewpoint of the above, a double pressurized container for under-cup charging according to the present invention comprises a container main body equipped with an opening at its upper end, a mounting cup attached for closing the opening, and an inner bag which has flexibility and also which is interposed between the container main body and the mounting cup, wherein the above-mentioned inner bag is equipped with a neck portion which is in close contact with an outer periphery of a rising wall of the mounting cup and also which abuts against that periphery with predetermined fitting strength.
Further, in this double pressurrized container, no gasket is provided in the curved flange of the mounting cup, the above-mentioned container main body is equipped at its opening with a bead portion, which is covered by a curved flange equipped to the mounting cup, and the inner bag, on the other hand, is equipped at its upper end with a flange portion which is engaged with the bead portion, which flange portion is given such defined shape, elasticity, or flexibility that it exhibits a sealing function when it is pushed against an inner surface of the curved flange with a charging pressure at the time of the under-cup charging. In another aspect of the above-mentioned double pressurized container for the inner bag, it has, for example, a lip shape such that it exhibits a sealing function when pushed against the inner surface of the curved flange with a charging pressure at the time of the under-cup charging.
In still another aspect of the double pressurized container, the above-mentioned inner bag flange portion has defined thickness and elasticity such that it exhibits a sealing function onto the container main body and the inner bag when it is clamped between the curved flange and the bead portion. Still another aspect of the double pressurized container, the flange, the container main body bead portion, and/or the mounting-cup curved flange are integrated into a line-sealing structure. Such a line-sealing structure can be realized by forming a continuous-annular irregular strip which meshes the inner-bag flange portion at a site where an outer surface of the container main-body bead portion and an inner surface of the mounting-cup curved flange, in which case when the flange portion is clamped between the bead portion and the curved flange, a line sealing structure is formed between the irregular strip and the flange portion. Also, the flange portion of the inner bag may have an annular step portion or thick portion, in which case that step portion or thick portion constitutes a line sealing structure when the flange portion is clamped between the bead portion and the curved flange.
The second aspect of the double pressurized container for under-cup charging comprises container main body equipped with an opening at its upper end, a mounting cup attached for closing the opening, and an inner bag which has flexibility and also which is interposed between the container and the mounting cup, the mounting cup having a plug inserted into an inner surface of the container main body with the inner bag therebetween and a cup-shaped cover made of metal sheet which covers the plug and which is crimped at its periphery against the outer periphery of the container body, wherein the inner bag has a cylindrical portion which abuts against the outer surface of the plug of the mounting cup closely with predetermined fitting strength, wherein the fitting size of the plug and that of the inner bag are such that the inner bag may be fit as being expanded slightly. In this preferred aspect of the double pressurized container, the container main body comprises a cylindrical portion at its upper part and an annular protrusion which protrudes inward at the lower part of the cylindrical portion, wherein the inner bag has another cylindrical portion which is fit to the cylindrical portion of the container main body and also the inner. bag is sealed when clamped between the side-wall step portion of the mounting cup and the annular protrusion. In still another aspect of the double pressurized container equipped with the above-mentioned plug and the mounting cup, it has a flange portion which covers the entire container main body and the upper end of the inner bag. In still another aspect, a gasket is interposed between the plug and the inner bag in order to seal them tightly.
In any of the above-mentioned double pressurized container, the inner bag may have a height enough to be supported at its bottom by an inner bottom of the container at the time of under-cup charging.
A double pressurized product according to the present invention comprises any of the above-mentioned pressurized containers, a concentrate charged in the inner bag of the pressurized container, and a propellant charged in a gap between the inner bag and the container main body.
A tandem-type double pressurized product according to the present invention features coupling the above-mentioned double pressurized products two at a time.
In the above-mentioned double pressurized container according to the present invention, the neck portion of the inner bag is in close contact with the outer peripheral surface of the rising wall of the mounting cup and also abuts against that surface, so that air-tightness is improved so as to prevent a propellant from entering the inner bag through the gap at the time of under-cup charging.
In still another aspect of the double pressurized container, size, elasticity and flexibility of the flange portion of the inner bag are predefined so that a sealing function may be exhibited when the flange portion is pushed against the inner surface of the curved flange with a charging pressure. Therefore, a tip of the flange is not easily lifted up, thus suppressing a propellant from entering through the lifted portion. A small amount of the propellant, even if entered, does not give rise to such a pressure as to expand a sealed portion because the neck portion of the inner bag strongly abuts against the outer peripheral surface of the rising wall of the mounting cup. With this, the propellant can be prevented from entering the inner bag.
In still another aspect of the double pressurized container, the outer periphery of the flange portion of the inner bag has a lip shape so that a sealing function may be exhibited when the outer periphery of the flange portion of the inner bag is pushed against the inner surface of the curved flange with a charging pressure at the time of under-cup charging. Therefore, at the time of under-cup charging, the outer periphery of the flange comes in close contact with the inner surface of the curved flange in order to be pushed against the inner surface of the curved flange more strongly with the increasing charging pressure, thus further suppressing leakage into the inner bag.
In still another aspect of the double pressurized container, the inner bag flange portion has predefined thickness and elasticity such that a sealing function may be exhibited between the container main body and the inner bag when the flange portion is, after assembly, clamped between the curved flange and the bead portion. With this, the inner bag operates in place of a conventional gasket, thus eliminating the necessity of the gasket. This bring about even easier close contact between the inner bag flange portion and the mounting cup curved flange inner surface, thus further improving a sealing function at the time of the under-cup charging.
With this, a smaller number of parts are required, thus facilitating assembly.
In still another aspect of the double pressurized container, the flange portion, the container main body bead portion, and/or the mounting cup curved flange are integrated into a line sealing structure. With this, after assembly, the force clamping the flange portion upward and downward is concentrated at one position on the line sealing portion, thus improving the sealing function as a pressurized product.
In still another aspect of the double pressurized container, such a line sealing structure is given by forming a continuous annular irregular strip which meshes with the flange portion of the inner bag, at such a site where the outer surface of the container main body bead portion and the inner surface of the mounting cup curved flange correspond to each other. With this, after assembly, the inner bag flange portion meshes with the bead portion at the irregular strip, thus obtaining a line sealing structure with a higher sealing function at that annular irregular strip. This effectively suppresses gas leakage after assembly.
In the second aspect of the double pressurized container, the mounting cup comprises a plug inserted into the inner surface of the container main body with the inner bag therebetween and a cup-shaped cover made of a metal sheet which covers the plug and also which has its periphery crimped to the outer periphery of the container main body, in such a configuration that the plug may be fitted, in size, to the inner bag while expanding the inner bag slightly. With this, there is given even stronger fitting between the mounting cup plug and the inner bag, thus further preventing a propellant from entering the inner bag at the gap at the time of under-cup charging. In this preferred aspect of the double pressurized container, the container main body comprises a cylindrical portion at its top and an annular protrusion at the bottom of the cylindrical portion which protrude inward, in such a configuration that the inner bag has a cylindrical portion fitted to the cylindrical portion of the container main body and also the inner bag is sealed when it is clamped between the mounting cup side step portion and the annular protrusion. Therefore, the inner bag may be sealed sufficiently.
In still another preferred aspect, the above-mentioned plug is equipped with a flange portion which covers the container main body and the upper end of the inner bag. With this, the inner bag and the container main body upper end are sufficiently protected by the flange portion. In still another preferred aspect, a gasket is interposed between the above-mentioned plug and the container main body upper end. With this, the inside of the container main body is sufficiently sealed from the outside. In still another preferred aspect, a gasket is interposed between the plug and the inner bag for sealing. With this, the above-mentioned gasket acts to provide a tight sealing function between the plug and the inner bag, thus sufficiently sealing the inside of the inner bag.
In still another preferred aspect of the double pressurized container according to the present invention, the inner bottom of the container main body supports the inner bag charged with a content at the time of under-cup charging. With this, it is not necessary to hold the inner bag when a propellant is charged and, also, the fitting between the inner bag neck portion and the plug is not shifted by a weight of the content.
The double pressurized product according to the present invention has the above-mentioned pressurized container charged with a concentrate and a propellant, so that little amount of the propellant enters the inner bag.
A tandem-type double pressurized product according to the present invention employs the above-mentioned type of the double pressurized product, so that each of the product may exhibit all the above-mentioned functions and effects. Also, it is possible to reserve two kinds of agents separately to eject them at the same time and mix them directly before use.